Apparatus for synchronizing an opaque video tape with a video display

ABSTRACT

An apparatus for synchronizing an opaque video tape with a video display including a means for continuously advancing the opaque video tape. An electron beam generator provides a beam of electrons that impinge the continuously advancing video tape and produce reflected electrical energy. A photodetector senses the intensity of the reflected electrical energy and provides an output signal having an amplitude related thereto. A sync circuit is coupled to receive the output signal provided by the photodetector and provides an output sync signal related to the reflected electrical energy.

United States Patent Stevens et a1.

[54] APPARATUS FOR SYNCHRONIZING AN OPAQUE VIDEO TAPE WITH A VIDEO DISPLAY Inventors:

[72] Eugene H. Stevens, Newbury Park; Paul A.

Sullivan, Los Angeles, both of Calif.

Hughes Aircraft Company, Culver City, Calif.

Filed: Nov. 17, 1969 Appl. No.: 877,326

Assignee:

U.S. Cl ..l78/69.5 TV, 178/DIG. 28, 250/219 FR, 250/71, 346/135 Int. Cl. ..l-l04n 1/02 Field 01 Search 1 78/695 TV, DIG. 28; 250/219 DR, 219 FR, 219 D, 71; 346/135 [56] References Cited UNITED STATES PATENTS 2,361,255 10/1944 Zworykin ..l78/69.5

[ 51 Apr. 25, 1972 2,594,358 4/1952 Shaw ..250/219 3,096,197 7/1963 Buetow et a1. ..250/71 3,290,437 12/1966 Goldmark et al.... ....l78/69.5 3,461,248 8/1969 Kane ..250/2l9 3,303,341 2/1967 Fram et a1 ..346/l35 Primary Examiner-Richard Murray Assistant Examiner-Peter M. Pecori Attorney-James K. Haskell and Frank E. Stevens, Jr.

[57] ABSTRACT An apparatus for synchronizing an opaque video tape with a video display including a means for continuously advancing the opaque video tape. An electron beam generator provides a beam of electrons that impinge the continuously advancing video tape and produce reflected electrical energy. A photodetector senses the intensity of the reflected electrical energy and provides an output signal having an amplitude related thereto. A sync circuit is coupled to receive the output signal provided by the photodetector and provides an output sync signal related to the reflected electrical energy.

8 Claims, 6 Drawing Figures PATENTEDAPR 25 I972 3, 6 359, 049

SHEET 3 BF 3 Ill] APPARATUS FOR SYNCI-IRONIZING AN OPAQUE VIDEO TAPE WITH A VIDEO DISPLAY BACKGROUND OF THE INVENTION This invention relates in general to an apparatus for synchronizing and more particularly to an apparatus for synchronizing a continuously moving opaque video tape to a video display.

One method that has been used in the past to synchronize a video tape with an external display has been to perforate a plurality of equally spaced perforations along the side of the video tape. A tooth is engaged in the perforations in the video tape and sequentially rotated a sufficient amount to advance the video tape from frame to frame.

However, where it is desired to continuously advance the video tape, the prior art method and apparatus can not be used for presenting a stationary picture. Applicant knows of no prior art to synchronize a continuously moving video tape with a stationary video display.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an apparatus for synchronizing a continuously moving opaque video tape with a video display.

The above and other objects of this invention can be attained by continuously advancing a scintillating opaque video tape and impinging the video tape with a beam of electrons provided by an electron beam generator. The impingement of the video tape with electrons causes photons to be emitted by the opaque video tape. The intensity of the photon emission is proportional to the surface image on the tape. The photon emission between frames will be substantially continuous. The photon emission is detected by a photodetector, the output of which is applied to a sync circuit. The sync circuit provides a sync signal related to the photon emission between the frames of the video tape.

Other objects, features and advantages of this invention will become apparent with reference to the following detailed description taken into conjunction with the accompanying drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial view of an opaque video tape having developed frames thereon;

FIG. 2 is a block diagram of an apparatus for synchronizing a continuously moving tape with a video display;

FIG. 3 is a voltage diagram of the output of a photomultiplier of FIG. 2 as it observes photons emitted from the continuously moving video tape;

FIG. 4 is a block diagram illustrating a method for synchronizing a continuously moving video tape with a video display and a video screen;

FIG. 5 is a block diagram illustrating an apparatus for providing a video display on a screen; and

FIG. 6 is a block diagram illustrating an apparatus for synchronizing a continuously advancing video tape with a video display.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, wherein like reference characters designate like or corresponding parts, there is shown in FIG. 1 an opaque bulk sensitized nucleation recording tape having a plurality of developed frames 22 thereon with a space 24 between individual ones of the plurality of developed frames 22. The opaque tape 20 illustrated in FIG. 1 can contain video frames 22 in the form of thin layers of metal wherein the thickness of the layers of metal varies in accordance with the image of the frame; such opaque tapes with images thereon are of the general type taught in H. G. Wehe U.S. Pat. No. 2,883,257, and in A. F. and E. E. Kaspaul U.S. Pat. No. 3,140,143. Those patents teach the production of a visible image by the condensation on the medium in imagewise configuration of a metal film from the vapor. Both of these prior art patents teach the deposition onto an opaque medium. Later development of the medium has produced improvements therein, but the result is still an image comprised of a metal deposit upon the medium. For example, where a relatively dark point of the image is to be projected, the layer of metal will be fairly thick and where a relatively light point is to be projected, the layer of metal will be fairly thin; thus, the medium is more reflective and the image is less reflective, as far as reflective light is concerned. The bulk nucleation recording tape 20 is an improvement over the media of the Wehe and Kaspaul patents, because it is sensitized in bulk. The image on the tape comprises the plurality of developed frames on the bulk sensitive nucleation recording material 26, which is mounted on a thin layer of aluminum 28, which is in turn bonded to a supporting substrate such as a layer 30 of Mylar. Mylar" is a polyester polymer film. Other desirable resinous films can be used. The bulk sensitive nucleation recording medium is a scintillator sensitive to electrons.

When the above described type of opaque video tape is impinged with electrical energy or electrons, the electrons will cause the scintillating medium to emit photons. Consequently, when electrons impinge the medium 26 directly, the greatest amount of photons will be emitted and therefore the greatest amount of light emitted by the phosphor medium. However, when electrons impinge individual ones of the plurality of developed frames 22, some of the photons will be attenuated according to the thickness of the layers of metal forming the plurality of frames 22, with the lightness and darkness of the images.

Referring now to FIG. 2, there is shown an apparatus for synchronizing a continuously advancing opaque video tape with a video display or monitor, including a means 32 for continuously advancing the video tape 20, a means 42 for providing a beam of electrons, a means 44 for detecting photon emission of the video tape 20 and a means 46 for producing a sync pulse.

The means for continuously advancing the video tape includes a frame 34, a storage wheel 36, a takeup wheel 38 and a rotating means 40. The storage wheel 36 and the takeup wheel 38 are rotatably mounted to the frame 34. The video tape 20 can be prewound or placed on the storage wheel 36 and fed to and wound around, or otherwise attached, to the takeup wheel 38 so that when the takeup wheel 38 is rotated, the video tape 20 will be transferred from the storage wheel 36 to the takeup wheel 38.

The rotating means 40 is connected to the takeup wheel 38 by a connecting means 39 and provides rotational motion to the takeup wheel 38. For example, if the rotating means 40 provides a rotational motion to the connecting means 39 in a clockwise direction, the takeup wheel 38 will be rotated in a corresponding clockwise direction as indicated by the arrows in FIG. 2. Therefore, when the video tape 20 is connected between the storage wheel 36 and the takeup wheel 38, the video tape 20 will be continuously translated from the storage wheel 36 to the takeup wheel 38, until all of the video tape 20 is translated to the takeup wheel 38. However, it should be apparent that the video tape 20 could be a continuous video tape which would continuously rotate from the storage wheel 36 to the takeup wheel 38 and back to the storage wheel 36.

The means for providing a beam of electrons 42 can be an electron beam generator that is connected to the frame 34. The electron beam generator provides a beam of electrons that continuously scan across the video tape 26. When the beam of electrons provided by the electron beam generator impinges the video tape 20, photons are emitted, as described for FIG. 1. The emission of photons is proportional to the thickness of the developed frames 22 at any point of a particular frame. It should be readily understood that the beam of electrons be produced in a vacuum. Consequently, the portion of the interior of the frame 34 wherein the electron beam imp- I inges the opaque video tape 20 must be under vacuum.

The means 44 for detecting light produced by the tape can be a photodetector that is connected to the frame 34 in substantially a perpendicular axis with respect to the video tape 20. The photodetector senses the intensity of the photon emission and provides an output signal as illustrated in FIG. 3, having a magnitude related to the intensity of the photon emission. Consequently, as the beam of electrons provided by the electron beam generator impinges the continuously advancing video tape 20, the emission of photons will vary.

The signals provided by the photodetector from time t, to time 1 and from time 2 to time t, correspond to the intervals of time when electrons from the electron beam generator impinge upon the image frames 22 of the tape 20 and correspond to video information. The output of the photodetector from time period to timeperiod t and from time period t to time period 1, corresponds to the output signal from the photodetector when the electron beam generator is scanning the video tape 20 on the spaces between the individual image frames 22. As can be seen by the output signal illustrated in FIG. 3, a sync signal corresponding to the interval of time when the electron beam is scanning the spaces 24 between the individual frames 22 can be provided by the output of the photodetector if the video information was removed therefrom.

There is further shown in FIG. 2 a sync circuit means 46 for producing a sync pulse. The sync circuit 46 is coupled to receive the output signal provided by the photodetector 44.

The sync circuit 46 removes or filters the video information signal from the output signal of the photodetector 44 and provides a sync output signal related to ,the pulse signal provided by the photodetector when the electron beam generator is scanning between the individual frames 22. The output of the photodetector could also be directly coupled to a video display 48, such as 1 a television monitor. If it is desired to synchronize the continuous. advancing opaque video tape 20 to a television monitor, the output signal of the photodetector 44 can also be applied to the video amplifier of the television monitor as illustrated in FIG. 2 and the output of the sync circuit 46 to the video monitor 48 sync circuit.

Operationally, the rotating means 40 rotates the takeup wheel 38 causing the video tape 20 to be continuously translated from the storage wheel 36 to the takeup wheel 38, As the video tape 20 is translated past the continuously scanning beam of electrons provided by the electron beam generator 42, electrons impinge the video tape 20 and photons are emitted by the video tape 20. The photodetector detects the photon emission and provides an output signal which is subsequently filtered by the sync circuit 46 to provide an output sync pulse for synchronizing the video tape 20 to the video display 48.

Referring now to FIG. 4, there is shown the embodiment of this invention illustrated in FIG. 2 that further includes a means for synchronizing a continuously advancing opaque video tape 20 with a display screen 50. In this embodiment, the output of the sync circuit 46 is further coupled to a light source or strobe light 52. The light source 52 provides a beam of light that impinges the video tape 20 and is reflected off the video tape 20 through the lens 54 and projected on a display screen 50. The output of the sync circuit 46 provides a sync pulse as described for FIG. 2 for synchronizing the strobe 52 so that the strobe 52 will provide a beam of light only during the intervals of time when any one of the plurality of individual frames 22 is in alignment with the lens 54.

Operationally, as the video tape is continuously translated from the storage wheel 36 to the takeup wheel 38, the sync pulse is provided by the sync circuit 46, as described for FIG. 2. The sync pulse is applied to the strobe light 52 for causing the strobe light to provide a beam of light to the video tape. The beam of light is reflected off the video tape 20 through the lens 54 onto the display screen 50.

Referring now to FIG. 5, there is shown another embodiment of this invention for synchronizing a continuously advancing opaque video tape 20 with a display screen 50. In this embodiment, the distance 24 between the individual frames 22 of the video tape 20 is sensed with a lamp 56 and a light detector 58.

In this embodiment, the video tape 20 is continuously advanced as described above and the sync circuit 46 provides a sync pulse signal to the strobe 52 as described above. However, in this embodiment, the signal provided to the sync circuit 46 is produced by a lamp 56 and alight detector 58. The lamp 56 is coupled to a positive voltage +E for providing a continuous source of light. The source of light provided by the lamp 56 is reflected off the video tape 20 in proportion to the density of metal on the surface of the video tape 20. The reflector light is sensed by the light detector 58 and applied to the sync circuit 46. The output signal provided by the light detector 58 will be substantially the same as the signal illustrated in FIG. 3.

The output of the sync circuit 46 is then applied to the strobe light 52. Consequently, as the video tape 20 is continuously advanced past the lamp 56, the light source is applied to the video tape 20. When the distance 24 between the individual frames 22 is exposed to the source of light, the reflected energy will increase in intensity and remain substan tially constant for a short period of time. As described above, the high frequency signal is filtered out by the sync circuit 46 and an output sync pulse related to the distance 24 between the individual frames 22 is provided. The output sync pulse is then applied to a strobe light source, causing the strobe to flash as described for FIG. 4, or the pulse may be applied to a video monitor.

More particularly, the lamp 56 could be positioned at a 45 angle with respect to the surface of the continuously advancing opaque video tape 20 which will cause a reflected light at a 45- angle with respect to the opaque video tape 20. The reflected light is sensed by the light detector 58 which will also be positioned at a 45 angle for maximum detection of the reflected light. 1

Referring now to FIG. 6, there is shown an embodiment of the present invention for synchronizing a continuously advancing transparent video tape 59 with a video display 48. In this embodiment there is shown a transparent video tape 59, a scanning means 60, a lens 62, a photodetector 64, a sync circuit 46, and the means 32 for continuously advancing a video tape. a The scanning means 60 provides a continuously scanning beam of light through the lens 62 .to the video tape 59. The scanning means 60 can be a scan type CRT scanner that provides a beam of light that continuously scans in a direction perpendicular to the movement of the video tape 59.

The light beam is projected through the lens 62 to the video tape 59. During the interval of time when individual frames 22 of the video tape 20 are exposed to the beam of light, some of the beam of light penetrates the video tape 59 and is sensed by the photodetector 64. However, when the beam of light provided by the scanning means 60 is exposed to the distance between frames, little or no light will be passed through the video tape 59 to the photodetector 64. The photodetector 64 provides an output substantially as illustrated in FIG. 3. The sync circuit 46 filters out the video information corresponding to the light passing through frames of the transparent video tape 59 and provides an output signal related to the distance between the individual frames of the video tape. As described for the other embodiment of this invention, the output of the photodetector 64 can also be applied to a video display 48 such as a television monitor.

While the salient features have been illustrated and described with respect to particular embodiments, it should be readily apparent that modifications can be made within the spirit and scope of the invention.

What is claimed is:

1. An apparatus for synchronizing with a video display an opaque video tape having a plurality of spaced video images thereon which images respond differently than the spaces therebetween to energy comprising:

feed means for continuously advancing the opaque video a beam generator means for providing a beam of energy to the opaque video tape, the beam of energy being directed to impinge on the opaque video tape for providing emitted energy;

detecting means for detecting the energy for providing an output signal related to the energy when said beam generator means directs its beam on the space between the images;

a sync circuit coupled to receive the output signal provided by said detecting means for providing an output signal related to the emitted energy to produce a sync signal when said detecting means detects the space between video images to indicate when individual ones of the plurality of video images are at a predetermined position; and

photon emissive illumination means directed toward said opaque video tape with spaced video images thereon for illumination of at least one of said video images, said illumination means being connected to said sync circuit for receiving the sync signal so that said illumination means responds to said sync signal to illuminate individual ones of said video images when they occupy a predetermined position.

2. The apparatus of claim 1 in which said detecting means is a photodetector.

3. The apparatus of claim 1 in which said illumination means is a strobe light.

4. An apparatus for synchronizing an opaque video tape having a plurality of spaced video images thereon along the length thereof which respond differently to light than the spaces therebetween comprising:

means for continuously advancing the opaque video tape in a first direction such that the images and spaces therebetween are successively advanced;

light means for providing a continuous non-scanning beam LII of light to the advancing opaque video tape, the continuous beam of light impinging on the opaque video tape a]- temately on the video images and the spaces therebetween due to the advancing of the tape for providing a reflected light signal in accordance with the portion impinged;

detecting means for detecting the reflected light signal for providing an output signal related to the reflected light signal of the portion impinged to detect the spaces between individual video images;

a sync circuit coupled to receive the output provided by said detecting means, said sync circuit providing a sync signal related to the different light signal resulting from the transition between the images and spaces when individual ones of the plurality of the video images are at a predetermined position; and illumination means directed at said continuously advancing image carrying opaque tape and coupled to said sync circuit for illuminating said tape when individual ones of said images are at said predetermined position.

5. The apparatus of claim 4 in which said light means is a lamp.

6. The apparatus of claim 4 in which said detecting means is a light detector.

7. The apparatus of claim 5 in which said detecting means is a light detector.

8. The apparatus of claim 4 wherein said illumination means comprises: 

1. An apparatus for synchronizing with a video display an opaque video tape having a plurality of spaced video images thereon which images respond differently than the spaces therebetween to energy comprising: feed means for continuously advancing the opaque video tape; a beam generator means for providing a beam of energy to the opaque video tape, the beam of energy being directed to impinge on the opaque video tape for providing emitted energy; detecting means for detecting the energy for providing an output signal related to the energy when said beam generator means directs its beam on the space between the images; a sync circuit coupled to receive the output signal provided by said detecting means for providing an output signal related to the emitted energy to produce a sync signal when said detecting means detects the space between video images to indicate when individual ones of the plurality of video images are at a predetermined position; and photon emissive illumination means directed toward said opaque video tape with spaced video images thereon for illumination of at least one of said video images, said illumination means being connected to said sync circuit for receiving the sync signal so that said illumination means responds to said sync signal to illuminate individual ones of said video images when they occupy a predetermined position.
 2. The apparatus of claim 1 in which said detecting means is a photodetector.
 3. The apparatus of claim 1 in which said illumination means is a strobe light.
 4. An apparatus for synchronizing an opaque video tape having a plurality of spaced video images thereon along the length thereof which respond differently to light than the spaces therebetween comprising: means for continuously advancing the opaque video tape in a first direction such that the images and spaces therebetween are successively advanced; light means for providing a continuous non-scanning beam of light to the advancing opaque video tape, the continuous beam of light impinging on the opaque video tape alternately on the video images and the spaces therebetween due to the advancing of the tape for providing a reflected light signal in accordance with the portion impinged; detecting means for detecting the reflected light signal for providing an output signal related to the reflected light signal of the portion impinged to detect the spaces between individual video images; a sync circuit coupled to receive the output provided by said detecting means, said syNc circuit providing a sync signal related to the different light signal resulting from the transition between the images and spaces when individual ones of the plurality of the video images are at a predetermined position; and illumination means directed at said continuously advancing image carrying opaque tape and coupled to said sync circuit for illuminating said tape when individual ones of said images are at said predetermined position.
 5. The apparatus of claim 4 in which said light means is a lamp.
 6. The apparatus of claim 4 in which said detecting means is a light detector.
 7. The apparatus of claim 5 in which said detecting means is a light detector.
 8. The apparatus of claim 4 wherein said illumination means comprises: a strobe light being coupled to receive the sync signal for producing a repetitive flashing source of light that impinges the video tape and projects the plurality of video images onto a display screen. 